Fig. 3. Plasma sodium, glucose, and sodium corrected for glucose levels in extremely preterm neonates, according to gestational age.

Each point represents the mean daily value; when multiple measurements were performed in a single day, the median value was kept. When no measurement was obtained, the daily value was extrapolated from linear interpolation of the two closest values. Plasma sodium and corrected sodium are shown as the mean daily change from baseline level (defined as the first plasma sodium measurement after birth), while glucose is shown as the mean daily absolute value. Error bars indicate the 95th confidence interval for the mean. Corrected sodium is calculated according to Katz.